In silico screening of potent bioactive compounds from honeybee products against COVID-19 target enzymes

Environmental Science and Pollution Research - After the early advent of the Coronavirus Disease 2019 (COVID-19) pandemic, myriads of FDA-approved drugs have been massively repurposed for...     

Incorporation of sewage sludge in clay brick and its characterization.

This study reports the use of sewage sludge generated from sewage treatment plant (STP) as raw material in a clay brick-making process. The physico-chemical and mineralogical characterization of the sewage sludge and clay were carried out in order to identify the major technological constraints and to define the sludge pretreatment requirements if necessary. Moreover, the effects on processing conditions and/or on changes of typical final characteristics are also evaluated. Bricks were produced with sewage sludge additions ranging from 10 to 40% by dry weight. The texture and finishing of the surface of sludge-amended clay bricks were rather poor. As for the physical and chemical properties, bricks with a sludge content of up to 40 wt.% were capable of meeting the relevant technical standards. However, bricks with more than 30 wt.% sludge addition are not recommended for use since they are brittle and easily broken even when handled gently. A tendency for a general degradation of brick properties with sludge additions was observed due to its refractory nature. Therefore, sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.     

Study of Thermal Decomposition Kinetics of Palm Oleic Acid-Based Alkyds and Effect of Oil Length on Thermal Stability

Thermal decomposition kinetics of three palm oleic acid-based alkyds with different oil lengths and having different molecular weights were studied using TGA measurements under non-isothermal conditions. Activation energies were obtained from Kissinger and Ozawa, Flynn and Wall (OFW) methods and subsequently the pre-exponential factor, A, degradation rate constant, k, for all the alkyds were also determined. From kinetic analysis of the thermal decomposition using the OFW method, it was found that degradation of all the alkyds has taken place in more than two stages, corresponding to different mechanisms. As shown from Ozawa and Kissinger methods, the chemical composition of the alkyds influenced the thermal degradation; increasing the phthalic anhydride and glycerol, and decreasing the oleic acid increased the thermal stabilities of the alkyds.     

Competitive role of nitrogen functionalities of N doped GO and sensitizing effect of Bi2O3 QDs on TiO2 for water remediation

The promising solar irradiated photocatalyst by pairing of bismuth oxide quantum dots (BQDs) doped TiO₂ with nitrogen doped graphene oxide (NGO) nanocomposite (NGO/BQDs-TiO₂) was fabricated. It was used for degradation of organic pollutants like 2,4-dichlorophenol (2,4-DCP) and stable dyes, i.e. Rhodamine B and Congo Red. X-ray diffraction (XRD) profile of NGO showed reduction in oxygenic functional groups and restoring of graphitic crystal structure. The characteristic diffraction peaks of TiO₂ and its composites showed crystalline anatase TiO₂. Morphological images represent spherical shaped TiO₂ evenly covered with BQDs spread on NGO sheet. The surface linkages of $\text{NO}?\mathrm{O}?\text{Ti}$, $\mathrm{C}?\mathrm{O}?\text{Ti}$, $\mathrm{B}\mathrm{i}?\mathrm{O}?\text{Ti}$ and vibrational modes are observed by Fourier transform infrared spectroscopy (FTIR) and Raman studies. BQDs and NGO modified TiO₂ results into red shifting in visible region as studied in diffused reflectance spectroscopy (DRS). NGO and BQDs in TiO₂ are linked with defect centers which reduced the recombination of free charge carriers by quenching of photoluminescence (PL) intensities. X-ray photoelectron spectroscopy (XPS) shows that no peak related to $\mathrm{C}?\mathrm{O}$ in NGO/BQDs-TiO₂ is observed. This indicated that doping of nitrogen into GO has reduced some oxygen functional groups. Nitrogen functionalities in NGO and photosensitizing effect of BQDs in ternary composite have improved photocatalytic activity against organic pollutants. Intermediate byproducts during photo degradation process of 2,4-DCP were studied through high performance liquid chromatography (HPLC). Study of radical scavengers indicated that ${\mathrm{O}}_2^{·?}$ has significant role for degradation of 2,4-DCP. Our investigations propose that fabricated nanohybrid architecture has potential for degradation of environmental pollutions.     

Effects of subchronic exposure to carbofuran on antioxidant defence system and malondialdehyde levels in common carp (Cyprinus carpio L.)

The present study focused on the assessment of oxidative stress induction by pesticides such as carbamates which are widely used as insecticides and nematicides and contaminate aquatic ecosystems on certain biomarkers in liver of common carp (Cyprinus carpio L.). Biomarkers selected for stress monitoring were malondialdehyde (MDA), an index of lipid peroxidation, and antioxidant defence system enzymes, mainly catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) activities in liver of fish exposed to 0, 10, 50, or 100?µg?L^?1 of carbofuran for 4, 15, or 30 days. Oxidative stress was found in liver of common carp exposed to carbofuran which was manifested by a decrease in CAT and GR activities after 4 and 30 days of exposure. An adaptive response was probably produced since at day 15 no modifications in the CAT activity and increased GR activity were observed. In addition, a decrease in MDA content with the highest concentration of carbofuran used was found after 30 days of exposure. However, no significant changes were found in GST activity showing a varied response. The results concerning oxidative and antioxidant profiles indicate that subchronic exposure to the insecticide carbofuran is capable of inducing oxidative stress in fish.     

Elucidation of phosphorous sorption by calcareous soils using principal component analysis

This study was conducted to understand the mechanisms governing P-sorption and desorption by calcareous soils (up to 48% CaCO ₃). Batch experiments with KCl as background were carried out by adding varying amount of P up to 100 mgP.L^?1. The desorption percentage (%DES) results show that little P was released from the adsorbed phase. Principal component analysis was applied to evaluate the combined influence of soil components on P sorption. The complex P sorption process can be related to specific soil components by the following equation: P? sorption=?2.20 (CaCO ₃% )?0.04 (Fe? oxide)+0.04 (pHe)+11.02 (sand % )+3.35 (silt)?10.73 (clay)?1.24 (EC)?0.22 (OM)?0.81 (CEC)?1.93 (P? Olsen) (R²=0.9941, SSE=380). Sand% and clay% are the most significant variables for modelling P sorption data. The derived equation could be applied to predict P sorption in other soils that have similar compositions to those investigated herein. The degree of P saturation (DPS) threshold level for all soils was less than 3% except in the soil with the lowest iron oxide. All of the studied soils have exceeded the environmentally unacceptable P concentration except the soil with the lowest iron oxide content.     

Time trends and predictive factors for safety perceptions among incoming South Australian university students

Problem

Young workers are over-represented in injury statistics. In order to develop injury prevention strategies, this study investigated time trends and predictive factors relating to safety skills, confidence, and attitudes.

Method

Annual surveys were conducted from 2006-2009 among incoming students at the University of Adelaide. The questions addressed safety training, injury experience, and health and safety perceptions.

Results

Time trends in training, perceived safety skills, confidence, and attitudes were not significant. In terms of skills and confidence, the most important correlate was safety training outside of high school (odds ratio = 1.6), especially when repeated, assessed, or in face to face mode. Feeling strongly about safety issues was best predicted by injury experience (OR = 1.7) and gender.

Discussion

These results emphasize the value of assessed training, but they are also consistent with published U.S. data, indicating no improvement over time. It is suggested that there be a more integrated approach in safety education, involving schools and workplaces.

Impact on industry

By developing an understanding of student safety perceptions and experiences, this research aims to target strategies to reduce the excess injury rate for young workers. Workplaces should be more aware of the limitations of school-based safety education and a more integrated and evidence-based approach should be developed, involving schools and workplaces.     

The interactions between tree-herb layer diversity and soil properties in the oriental beech (<Emphasis Type="Italic">Fagus orientalis</Emphasis> Lipsky) stands in Hyrcanian forest

This study investigated the interactions between tree-herb layer diversity and some physico-chemical and eco-physiological characteristics of soil in natural oriental beech stand in western Guilan, Iran. The data were collected from nine research sites (50 m?×?50 m) which were described as a gradient from pure oriental beech (Fagus orientalis Lipsky) stands to mixed stands with up to nine deciduous tree species (n =?27) in Hyrcanian forest. Herbaceous plants were sampled within ten 1 m?×?1 m sub-plots in two plots of 400 m² which were installed randomly in each research site. Composite soil samples were taken at five positions in each research site. We found that the increase in tree diversity in mature oriental beech stands brought about an increase in microbial biomass carbon, soil carbon content, and the ratio of microbial biomass carbon to the organic carbon (C_mic/C_org). Increased soil organic carbon raised microbial biomass carbon through creating suitable environment for microorganisms. The findings also indicated that the ratio of microbial biomass carbon to the organic carbon (C_mic/C_org) increased as a quantitative indicator of soil carbon dynamics that finally benefits soil fertility of mixed oriental beech stands compared to pure oriental beech stands. The results showed that humus layer and litter thickness were negatively correlated with tree layer richness. Generally, it can be stated that maintaining a mixture of tree layer species in natural oriental beech stands results in an increase in richness and diversity values of herb plants as well as carbon content and microbial biomass carbon of soil.